The field of the invention pertains to dermatomes generally, and in particular an improved dental surgery dermatome useful in the treatment of mucogingival defects involving inadequate attached gingiva. In such treatment, a graft or grafts of tissue are removed from the palate to increase the zone of attached gingiva.
In previously known practice, a scalpel was employed to make two elongate parallel cuts vertically through the epithelium, into the underlying connective tissue to delineate the long side boundaries of the graft, whereafter the graft would be removed starting with a horizontal incision at one end of the parallel cuts and removing a thin layer of palatal mucosa. This procedure provided a suitable graft but left the donor site with deep parallel wounds into the connective tissue which required healing before epithelial cells from the boundary areas could migrate over the wound. As a result, the healing process was unduly prolonged and, in most cases the patient would not be comfortable again until 21/2 to 3 weeks elapsed after surgery.
More recently, a dermatome was developed including a bowed or unbowed blade, permanently or removably mounted at the end of a handle, the cutting edge of the blade being U-shaped or flat. Such blades are difficult to use in that the depth of the cut cannot be controlled other than by the experienced hand of the surgeon. Should the cut be too shallow, the graft will not take after implanting; if the cut is too deep, fatty tissue and glands will be removed which will have to be trimmed before grafting, and healing of the wound at the donor site will be even further prolonged. Furthermore, the blade tends to wobble, flex and undulate from side to side during the cut, due to lack of support for the blade, thereby leaving an uneven wound at the donor site and graft tissue that should be further trimmed prior to grafting. Additionally, the looped configuration of the blade produces a graft having shallow side edges that will slough off during healing or must be trimmed prior to grafting. In any event, even though such dermatomes represent a significant advance in the art, deficiencies remain as enumerated above which are overcome by the present invention.
The prior art includes several U. S. patents evidencing a development in similar surgical cutting instruments. Curettes having permanently mounted open or closed blades are disclosed in U. S. Pat. No's. 467,188; 872,567; and 2,521,161. Similar devices having removable blades are disclosed in U. S. Pat. No's. 3,013,553; 3,221,744 and 3,367,335. U. S. Pat. No. 3,502,082 issued to Chatfield discloses several varieties of a looped blade useful in dental surgery as discussed above, the looped blade assembly being disposable and replaced after use, but the blade is not adjustable to a suitable cutting angle with respect to the handle, as may be required when the donor site is located in a high vaulted palate. Adjustable non-looped blades useful in dental surgery are disclosed in U. S. Pat. No. 3,471,929, issued to Boone, but these blades are expensive to manufacture.
U. S. Pat. No. 3,688,407 issued to Omer E. Paquette discloses a looped blade dermatome now in use in dental surgery, the blade being replaceable and made by merely trimming an edge from a common stainless steel razor blade. Additionally, the blade may be secured at various cutting angles relative to the handle and the blade may be shaped to provide a bowed contour or it may be a flat, unbowed blade strip.
However, even in the case of the Paquette knife, depth control of the cut is not provided nor is side to side undulation of the knife prevented. Furthermore, no means are provided to assure that the present configuration of the blade (bowed or flat) will be retained during use.